For more than 30 years various scoring systems have been used as a method to asses the injury severity of multi-system trauma. They have been used as a tool for triage, for emergency-room quality management, for educational reasons or, nowadays, in order to evaluate the cost effectiveness of either a complete hospital or a single department. This review provides the knowledge to score multi-system traumatized patients after their first treatment in the emergency-room. It shows advantages, disadvantages, and limitations of various traumascores which includes knowledge about the used parameters, the type of validation, the medical system in their country of origin, and of course their mathematical background. Relevant examples like physiological trauma scores (GCS, RTS, MEES), anatomic, injury pattern based scores (ISS, NISS, ICISS), biological aspects, mixed scoring systems (PTS, TRISS, ASCOT) and future developments ("Rixen-pattern", RISC) are illustrated. These scores are explained in detail and discussed as to their practicability.